Cap upgrades (bear with me)

[STURMJ]

It has been said previously, that the last power supply cap may improve the performance if upgraded.

[adamct]

Thanks, Brad. I do have the Speedball installed. When you say you bypassed the last cap, are you referring to bypassing one of the caps in the power supply?

Best regards,
Adam

[Grainger49]

The last cap in the power supply has the audio signal returning through it.  So it does have an effect on the sound.  This is the cap that is on the left side of the transformer, closest to the front of the chassis.

[adamct]

Thanks, Grainger. And that one is 220uF 250volts, correct?

Best regards,
Adam

[Grainger49]

Yes, it is 220uF@250V.

[m17xr2b]

Where exactly should the bypass cap be added for the last cap in the power supply(what terminals). Is 2.2uf 250 a good choice?

[Grainger49]

Bypassing is simply paralleling a better, smaller value cap with the existing cap.  Since film caps are not polarized you pick one lead for the plus the other is the minus lead.  Getting them on the terminal strip will be not so much fun.  Maybe wrap the leads around the bare legs of the existing power supply cap?

[m17xr2b]

Would a mundorf 2.2uf 250V mkp be a good choice to bypass the last cap in the power supply?

[BNAL]

That value will work. I connected one leg of the bypass cap on 11U and the other to B5 on the octal socket. The size of the cap I was using made it too difficult to try and connect to the other leg if the cap.

[earwaxxer]

I like Mundorfs as bypass caps.

[adamct]

Sigh. My caps arrived today.  The damn things are huge. And the leads are short. At a minimum, I'm going to have to raise the case height. In the mean time, I have three other concerns/questions:

1. I assume I will have to install "fly leads", which I also assume are just bits of wire that run between the leads on the caps, and the terminals they are supposed to be soldered to. Basically just extension cables for the caps, is that right? Can i just use a bit of the hookup wire i have left over from the Crack kit? Does having leads that long raise any concerns (e.g., risk of picking up interference, etc.)?

2. My caps are ClarityCaps from the ESA series. The outside looks like it is aluminum foil. I assume it would be a bad thing if the cap were to touch other things in the Crack? The one on the left would be at risk of touching terminal 11, the resistor between terminals 12 and 13, and probably a couple of the terminals on the octal socket. That can't be bad, right?       The one on the right would be at risk of touching terminals 17 and 18, whatever octal terminals the left cap isn't touching, and...um...the left side cap itself.

3. I assume I should just give up and send these caps back, correct? 

So frustrating...

[adamct]

In case you are in need of a good laugh, here are a few pics to show the caps. I took pictures of the caps in both orientations to show that they don't really fit either way...

(https://www.head-fi.org/image/id/3884568/width/900/height/900/flags/LL)
(https://www.head-fi.org/image/id/3884569/width/900/height/900/flags/LL)
(https://www.head-fi.org/image/id/3884571/width/900/height/900/flags/LL)

Grrrrrrrrrrrrrrr!
Adam

[Alonzo]

Ha!!! 
You should check out the Gallery section of the forum; plenty of very big caps there.  You'll find plenty of company in the big cap zone....
http://www.bottlehead.com/smf/index.php/topic,3370.0.html is my Crack amp.

[adamct]

I know others have done it, but give that the outside of mine seems to be tin foil, I can't help but feel it will be dangerous if I install them. I can't tell if there is a plastic film covering them...

[dwilli852]

If you want to use film caps you'll have to deal with the space problem.

You can use an Ohm meter to see if the outside is conductive.

I added about 3 inches in height to the base of mine along with a cross brace at the bottom and tie wraps to hold the Auricaps I'm using.

I started off just adding some wire to the leads and setting the caps outside of the orignal base.

Didn't look too good but worked fine.

The ESA's should sound good I've used them in several speaker projects.